In the problem of mutual exclusion, concurrent access to a shared resource or the Critical Section (CS) must be synchronized such that at any time, only one process can access the CS. In a real-time distributed system and a system which uses priorities for scheduling, events for requesting the CS should be ordered on the basis of priorities of the processes (as first proposed in Goscinski's algorithm) rather than on the basis of the time when those events happened. In this paper, we show how to modify several well-known distributed mutual exclusion algorithms (which are based on the time when these events happened) so as to be prioritybased mutual exclusion algorithms for real-time distributed systems.

Received September 6, 1993; revised August 15, 1994.
Communicated by Shing-Tsaan Huang.
*This research was supported by the National Science Council of the Republic of China, Grant No. NSC-81-0408-E-110-508.